Hepcidin‐25 vs. conventional clinical biomarkers in the diagnosis of functional iron deficiency

Objectives As hepcidin-25 is considered as a key regulator of human iron homoeostasis, this study aimed to compare this parameter with conventional biomarkers and diagnostic tools of iron deficiency (ID). Methods In total, 233 hospitalised adult patients, who underwent routine blood testing for ID, were included. All subjects were investigated for hepcidin-25, reticulocyte haemoglobin content (CHr), soluble transferrin receptor (sTfR)/log ferritin ratio (i.e. Thomas plot), sTfR, ferritin, transferrin saturation (TSAT), C-reactive protein (CRP) and for complete blood cell count. Functional ID was defined as a CHr   0.5 mg/dL) acute-phase reaction, respectively. Results One hundred seventeen patients with CRP > 0.5 mg/dL showed a distinctly higher hepcidin-25 median value [35.60 (range: 4.27–80.03) ng/mL] as compared to 116 patients with CRP ≤ 0.5 mg/dL [18.55 (range: 3.77–73.01) ng/mL]. With respect to functional ID, sTfR/log ferritin ratio and sTfR were of better positive predictive value (PPV) (sTfR/log ferritin ratio: 58.33% and 70.83%; sTfR: 60.00% and 60.00%) than when compared to hepcidin-25 (PPV: 37.74% and 42.86%) and ferritin (PPV: 27.54% and 46.15%) in both subgroups. Conclusions The sTfR/log ferritin ratio, as well as sTfR, were better predictors of functional ID in patients with and without acute-phase reaction as compared to hepcidin-25 and ferritin.